Seat with a tilting and folding back

Abstract

The seat in which the back (12) may be tilted relative to the base (11) comprises a support (120) and a frame (20) with end plates (21, 22) between which is interposed a tilt-adjustment device (30) and a pivot mechanism (50) with a cheek (51) between support (120) and end plate (22), a lock (52) for holding back the back, a linkage piece (53) connecting this device (30) and this lock (52) and a safety device (54) preventing the back from folding down into a virtually horizontal shelf unless the back is placed in the upright position beforehand. Application to the seats of motor vehicles.

What is claimed is: 
     
       1. A seat (10) comprising, in combination; a base (11);   a back (12) carried by a back support (120) tiltable relative to said base (11) between an upright position and other tilted positions changeable at will;   a frame (20) having on each of two opposite sides thereof a pair of end plates, each pair having a first end plate (21), for accommodating said base (11), and a second end plate (22) for accommodating said back support (120); `tilt-adjustment means (30) inserted between said first and second end plates (21, 22) and movable between a normal blocked locking position, toward which said means (30) is normally biased in order to fix a relative position of said back (12) and base (11), and a transitional released free position to allow an adjustment of a tilted position of said back (12) relative to said base (11), said tilt-adjustment means (30) being provided with a control means (31) for changing the position of said tilt-adjustment means; and   a pivot mechanism means (50), placed between said second end plate (22) and back support (120), for making said back (12) movable between a first normal position, where said back (12) serves as a back rest, and a second folded position where said back (12) serves as a shelf;   said pivot mechanism means (50) comprising:   at least one cheek (51) carried by said back support (120) and rotatably mounted on said second end plate (22) for rotation about an axis between said first and second positions;   a lock means (52) having a catch and a bolt cooperating with said cheek (51) and said second end plate (22) and movable between a first active position, toward which it is normally biased to fix said back (12) in one of its said first normal and second folded positions, and a second inactive position to tilt said back (12);   a linkage means (53) connecting and controlling said tilt-adjustment means (30) and said lock means (52) either in order to act on said control means (31) to move said tilt-adjustment means (30) from one to the other of its said usual and transitional positions, or in order to act and move said lock means (52) from its said active position to its said inactive position; and   safety device means (54), pivotally mounted on said second end plate (22), and biased by a spring (544) for contacting and cooperating with said first end plate (21) and for acting on said cheek (51) to lock said cheek (51) and prevent any rotation thereof which would place said back (12) in its said shelf second folded position when said back (12) is not placed in its upright position beforehand.   
     
     
       2. Seat according to claim 1, wherein said catch of said lock means is fixedly mounted on said cheek (51), and said bolt of said lock means is articulatedly mounted on said second plate (22). 
     
     
       3. Seat according to either of claims 1 or 2, wherein the catch of the lock means (52) comprises a deformed piece (511) in the shape of a sector of a circle centered on said axis (510), and wherein said deformed piece has a peripheral edge which carries recesses (512, 513) defining the first normal position and the second folded position, respectively. 
     
     
       4. Seat according to claim 3, wherein the bolt of the lock means (52) comprises a lever (520) mounted so as to pivot about a pin (521) of the second end plate (22), said lever having a first end, which carries a nose (522) adapted to engage in the recesses (512, 513), and an opposite end which carries an operating arm (523). 
     
     
       5. Seat according to claim 4, wherein the linkage means (53) comprises an angled bracket (530) articulated about a pin (531) of the second end plate (22), one of two opposite ends of said bracket (530) being provided with a clamp (532), adapted to be connected to the control means (31), and having an elongate opening (533) adapted to accommodate a roller (524) carried by the bolt of the lock means (52). 
     
     
       6. Seat according to claim 4, wherein the safety device means (54) comprises a latch (540) which is mounted pivotably on a pin (541) of the second end plate (22), which has a tooth (542) adapted to interact with a notch (211) of the first end plate (21), and which has a toe (543) adapted to interact directly or indirectly with said cheek (51). 
     
     
       7. Seat according to claim 1 or 2, wherein the linkage means (53) comprises an angled bracket (530) articulated about a pin (531) of the second end plate (22), one of two opposite ends of said bracket (530) being provided with a clamp (532), adapted to be connected to the control means (31), and having an elongate opening (533) adapted to accommodate a roller (524) carried by the bolt of the lock means (52). 
     
     
       8. Seat according to claim 7, wherein the safety device means (54) comprises a latch (540) which is mounted pivotably on a pin (541) of the second end plate (22), which has a tooth (542) adapted to interact with a notch (211) of the first end plate (21), and which has a toe (543) adapted to interact directly or indirectly with said cheek (51). 
     
     
       9. Seat according to claim 1 or 2, wherein the safety device means (54) comprises a latch (540) which is mounted pivotably on a pin (541) of the second end plate (22), which has a tooth (542) adapted to interact with a notch (211) of the first end plate (21), and which has a toe (543) adapted to interact directly or indirectly with said cheek (51).